1. Field of the Invention
The present invention related to an IC card-type radio communication device, and more particularly, to an IC card-type radio communication device in which both a radio data communication and a conversation are executed using a portable telephone.
2. Description of the Related Art
Of a traditional radio communication device, the portable telephone is connected to a modem (modulator and demodulator) or an IC card which executes a digital signal processing through a cable for a signal wire, when the radio communication is executed by using the portable telephone. For instance, a digital data transmitted from a personal computer is modulated by the modem installed on the IC card to obtain an analog signal.
The analog signal is outputted to a head set terminal of the portable telephone by the cable, and the analog signal is modulated into a radio signal by the portable telephone. The radio communication is executed by the modulated radio signal.
However, the conventional radio communication device includes the portable telephone, the IC card installed on the modem and the cable. For this reason, an operational performance of the device is deteriorated and the cost is rather high.
Another conventional radio communication device exists. Which unifies the portable telephone and a modem circuit through the cable so that the operational performance will be improved.
However, such accessories as the cable and RS232C connector are necessary for connecting the personal computer to the modem circuit. Also, it is difficult to make the accessories portable, since the RS232C connector itself is relatively large.
Further, an example 3 of the traditional radio communication device exists. In which, an interface between the personal computer and the portable telephone is formed in accordance with a standard of Japan Electronic Industry Development Association (JEIDA)/Personal Computer Memory Card International Association (PCMCIA). However, a cable for connecting an earphone or a microphone to the portable telephone is needed, when the portable telephone is used for a conversation.
Also, an IC card mentioned in 140895 number of an official report of patent disclosure in 1992 was used for the radio communication, and it was miniaturized to the size of a business card. However, a dedicated interface for connecting the IC card to a host computer is needed.